Preparation of halothenyl halides



Dec. 23, 1952 H. D. NoRRls 2,623,049

PREPARATION op HALOTHENYL HALIDES Filed March 18, 1947 C4 H0142) 5x22 @ff-2 .//x CONDE/v5.6@

INVENTOR Patented Dec. 23, 1952 PREPARATION OF HALOTHENYL HALIDES Henry D.`Norris, Woodbury, N. J., assigner to Socony-Vacuum Oil Company, Incorporated, a

corporation of New York Application March 18, 1947, Serial No. 735,338

1 The present invention relates to the preparation of halothenylhalides and, more particularly, to the preparation" of halothenyl chlorides.

The haloalkylation of .aromatic compounds was rst described` iby .Grassi and Masselloin 1898. These investigators prepared benzyl chloride from benzene, vformaldehyde and hydrogen chloride in the presence of zinc chloride. In a discussion of the replacement of a hydrogen atom by a halomethyl group in a single operation, Fuson and McKeever `.[Organic ReactionsEd. Roger Adams (John Wiley,& S`on`S,.II1C.-) A(1942)] at page 64 et seq. makeseveral statements of interest. These authorities-state:

. chloromethylation is generally'applicable to aromatic compounds. Benzene, naphthalene, anthracene, phenanthrene, ybiphenyl and many of their derivatives have' been converted to chloromethyl derivatives. 'TerphenyL however, resists chloromethylation altogether The presence of a' halogen atom on'the ring causes the reaction to .'bemorediicult'tof-effect. Although such compounds-'as bromo'- and chlorobenzene, bromoand chlorotoluenes,v and p-v ly reactive :compounds of' many .sorts-naphthalene, anisole, phenols, polymethylbenzenes, ete-tend to yield'zthistype.of;product,"and it is often difcult or impossiblefto-:isolate rthe intermediate chloromethyli derivative.

In view of the statements ofY the'sefauthorities that halogenated .derivativesgenerally failto undergo chloromethylation.and that highly reactive aromatic compounds yield diarylmethane derivatives, it is surprising vto discoverthat halothiophenes yield halomethyl derivatives. in good yields and notthe.correspondingdithienyl methane derivative. y

It is an` object. of the present. invention topravde a methodior vhaloallzy-lating,.halogenated thiophenes.v It is `anotherobject .ofv the present invention to .provide VaI method for preparing haloalkyl halothiophenes a single.. step .from vhalothiophenes. It is .aiurth'er vobject. ofthe-present invention to prQvide v`lhaloalkylhalothiophenes. Other. objects -and `.adv'antlif2s Willzibeoome .apparent from the.followingdescription. V

A study. of the `.literatureoi-the;preparation -.of haloalkylhaloaromatic.compoundsby haloalkylat- 17 claims. (c1. 26o-332.5)

ing haloaromatic compounds :leads .to .the con.- clusion .that rather vigorous conditions. yare required. That is vto say, the `single step method for preparing haloalkyl haloaromaticcompounds has required the use of a .dehydratingf .catalyst such as zinc chloride, .phosphoric acid, sulfuric acid or -zinc .chloridefaluminum chloride; Waterfree paraforma'ldehyd'e and. gaseous yhydrogen chloride.

Blanc; Bull. Soc. Chem., (4) 33, 313 (1923).

Vavon; ibid, (5) 6, 1025 l(1939).

Fieser; J. Am. Chem. Soc.5'f7, 942 (1935).

Smith; ibid, 62, 1349 (1940).

Bruce and Kahn; ibid, vv60. 1017 (1938).

Stephen, Short and Gladding; J. Chem. Soc. 117,

Horn and Warren; ibid,` 1,946, 144.

Tschunkur & Eichler; D. R. P. 509, 149; C. A., 25,

Chem. Zentr. 1102, 1, 360 (1931).

or a-thienylmethyl chloride by chloromethylation of thiophene. These investigators Were able. to convert 40 per cent of thethiophene to athieny1 methyl chloride and 38 per cent to di-a-thienylmethane STL/S l H l by treating a mixture of thiophene, concentrated hydrochloric acid and formaldehyde. with al rapid stream of hydrogen chloride. That is to say, these investigators `foundrit necessary to employ rather severe conditions, in order to chloromethylate thiophene in 40 per cent yields. It will also be noted that an equivalent amount of thiophene was converted to the dthienylmethane derivative.

Steinkopf states that Biederman reported in Berichte Deutsche Chemische Gesellschaft 19, 639, 1620 (1886) the preparation of 2-thenylchlofrom Z-thenylalcohol,

tlg..

and hydrogen chloride. Steinkopf reported in Liebigs Annalen die Chemie 513, 281 (1934) that by direct bromination of Z-methylthiophene a mixture of 3-bromo-Z-methylthiophene and 5- bromomethylthiophene is obtained as well as the almost symmetrical 3,5 dibromo 2-methylthiophene. Further bromination led to the production of 3,4,5 tribromo 2 methylthiophene. In this preparation, however, one must be cautious since it is readily attacked in the side chain and according to the conditions converted into 3,4,5- tribromo-Z-thenylbromide chloroor bromothenyl halides which correspond broadly to the formula (XMCILX where X is iodine, bromine or chlorine and m is l to 3. Thus, for example, 2-ch1orothiophene,

can be converted into 5chloro-Z-thenylchloride,

ClLS/ICHZCI 2,5-dibromothiophene,

can be converted into 2,5-dibromo-3-thenylchloride,

-oHzCl Br L )Br S 4 2,3,5-trchlorothiophene,

can be converted into 2,4,5-trichloro--3-thenylchloride,

and the same or similar compounds can be converted into the thenyl bromides in a single step direct operation. In a corresponding manner, homologs corresponding to the formula where X is iodine, bromine or chlorine, m is 1 to 3 and n is 1 to 4, and corresponding to the formula H @mit #l1-X S where X is iodine, bromine or chlorine and m is 1 to 3, can be prepared using alicyclic, heterocyclic and aromatic aldehydes,

Illustrative of the foregoing are the following non-limiting examples.

EXAMPLE I (5-chZoro-2-thenylchloridm In a discontinuous operation, 5 chloro -2- thenylchloride can be produced in a single step direct reaction from 2-chlorothiophene in the following manner. Concentrated hydrochloric acid and 2-chlorothiophene are placed in a container provided with a stirrer, a reux condenser, a discharge port, means for heating and cooling the reaction mixture and similar conventional auxiliary equipment. The hydrogen chloride and the 2-chlorothiophene are used in a ratio of about 7.04 moles of hydrogen chloride to about 1 mole of 2-chlorothiophene (boiling point 122-130 degrees centigrade) To the well stirred mixture of 2-chlorothiophene and hydrochloric acid about 1.85 moles of an aqueous solution of formaldehyde having a concentration of 36 to 38 per cent, and generally known in industry as Formalin solution, is added. The reaction temperature rises spontaneously and is maintained at about 40 degrees centigrade usually without the application of additional heat. After two hours stirring at 40 degrees centigrade, the temperature of the reaction is raised to 60 degrees centigrade, and maintained at that temperature whilst agitating the reaction mixture for an additional two hours. The reaction is then stopped by quenching, for example, in water employing, preferably, about two volumes of water for each volume of reaction mixture. The quenched mixture is then extracted with petroleum ether or other suitable solvent for the oily reaction product, and the extract thoroughly washed with Water until neutral. The washed extract is separated from the wash water in any suitable manner and dried in any desired manner, for example, with anhydrous sodium sulfate. The extract is then separated from the drying agent and the solvent removed, for example, on a steam bath. A distillation of the crude product provided the following two distillates and a still residue:

o C' mm Hg f stllcharge chloroi thiophene I. B P se 2o '9o I2,0 A23.2 17 2 100 2O 65.2 50 Residue 11.6

It is `manifest that most of the fdistilled :product is 5'chloro2thenyl chloride While unreacted chlorothiophene is removedfon'theg steam bath.

A portion of each of cuts vI and i]A Were comibined and reacted with potassium ethyl l-xanf thate. The product obtained, i. e. 5,-chlorof`2- thenyl ethyl xanthate, was analyzed.

EXAMPLE II (2,5dibromo-S-thenylchlorid Concentrated hydrochloric acid, agueous 37 per cent formaldehyde and'2,5dibromothiophene are mixed in the molal proportion of about 2.42 moles of formaldehyde and about 17.6*moles of hydrogen chloride per mole of 2,5-dibromothiophene. The reaction mixture is heated to about 80 degrees centigrade with agitation for about 6 hours. Thereafter, the reaction mixture is cooled to about 50 degrees centigrade andthe oily lower layer of reaction product separated from the aqueous upper layer. The product is dried, say, with sodium carbonate or in any other suitable manner and the dried-crude product'distilled under reduced pressure. The following is a log'ofthe distillation of va portion'of-the dried product.

Cut 6 gave 1.830Wgrams of y silyerghalide per gram of compound. The theoretical. yieldoff'sil- Ver halide for 2,5-dibromo-3fthenyl chloride-is 1.7864 grams. Q

2,5-dibrorno-3t'heny1 ethyl xanthate,

1| TCHe-S-C-O 02H5 BiL Br S/ was prepared and analyzed.

Calculated `Observed EXAMPLE -fIII (2,5-dzchloro-3-thenyl chloride) An aqueous solution of formaldehyde containing about 37 per cent formaldehyde, concentrated `hydrochloric acid Sand v2,5-dichlorothiophene are mired in l'the molal ratio of 17.8 moles of formaldehyde andy 96l molesof hydrogen chloride per mole of 2,5-,dich1orothiophene. The reaction mixture is heated with agitation to about 73 degrees centigrade for about 6 hours. Thereafter the reaction mixtureis cooled and the organic layer separated from the aqueous layer. The oily organic layer is dried in any suitable manner, for example, with anhydrous magnesum sulfate and sodium carbonate. The oilis separated from the drying agent and distilled under reduced'pressure. The log of the distillation is as follows:

n Percent A cutNo. Tgp" glslw 'weighmfi NDQQ -g- Astillcharggo 141 y15 3.7 1. 5621 1'5A 19;() 1.5630 15, 6.0 1.5661 15` A2.2 1.5669 15` 1.0 1.5730 15 2. 5 1. 5838 15 16.5 1. 5846 '15 '17; 5' 1. 5846 14V 15.0 I, 5844 5` 2. 2. 1.5861 5' 4.7 1:5929 3l0 6.7.

Material.representativeof cutsf6,f`l, Sand 9 and believed toV be 2,5-dichlo`rof3fthenyl chloride, was analyzed for sulfur and chlorine.

`. Calculated Observed CGHQSOIB Percent Percent Cl 52. 52. 02 S 15. 9 16. 1

EXAMPLE IV (2,4,5-trichZoro-,3-thenyl chloride) 7 der reduced pressure. A log of such a distillation is as follows:

Percent weight of still charge Pressure.

Temp.,

C. mm. Hg

which when analyzed for chlorine gave the following value:

Calculated Observed Percent Percent CH2SC14: Cl

In the foregoing examples the reaction between mono, chloro, dibrorno, dichloro, and trichlorothiophenes, formaldehyde and hydrochloric acid has been described in detail. The correspending iodine derivatives react in an analogous manner. That is to say, mono-, diand triiodothiophene can be reacted with formaldehyde and hydrochloric acid in the same molal ratio as the corresponding chloroand bromothiophene compounds to produce mono, diand triiodothenyl chloride. Furthermore, in precisely the same manner and employing the same molal proportions monochloro, dichloro, trichloro, monobromo-, dibro1no, tribromo, monoiodo, diiodoand triiodothenyl bromides, iodides and chlorides can be produced by the use of hydrobromic acid, hydriodic acid and hydrochloric acid, respectively, in conjunction with formaldehyde.

The length of the side chain of the halothiophene substituted alkyl halides or halothionyl halides can be varied by the use of aldehydes other than formaldehyde. For example. by the use of paraldehyde and one of the hydrogen halides, HC1, HIBr or HI, a material corresponding to the formula S CHXCH;

where X is I, Br or Cl and n is 1 to 3, can be obtained. Similarly, products corresponding to the formulas S CHXCHZCH and S oHXoHiCHiCH,

where X is I, Br or C1 and n is 1 to 3, can be 8 obtained by using propaldehyde and butraldehydev and the desired hydrogen halide.

The foregoing discussion and description of specific nonlimiting illustrations of this embodiment of the invention establishes that the present invention provides a one step method for the preparation of halothiophene substituted alkyl halides or halothenyl halides from halothiophenes, using aliphatic aldehydes having 1 to 5 carbon atoms and hydrogen halides other than hydrogen fluoride. Consequently, when the term halides is used herein it excludes hydrogen uoride as is general in a discussion of the reaction between compounds of carbon and the halides. In general, the reactants are used in such molal proportions as to provide an excess of the aldehyde and a large excess of hydrogen halide. Reaction temperatures above ambient temperature up to reflux temperature may be used. The time of reaction increases as the number of halogen substitution groups in the thiophene derivative increases and as the molecular weight of the aldehyde increases.

Although the preparation of halothenylhalides has been illustrated hereinbefore by discontinuous operation, the same materials can be prepared in an analogous manner in a continuous operation. Generally speaking, satisfactory results are obtained by reacting the liquid halogen substituted thiophene with vapors of an aldehyde and a halogen halide in the presence of highly porous absorptive material or solid adsorbent contact material as hereinafter defined. The reaction is carried out in such a manner that the halogen substituted thiophene is contacted in the presence of solid highly porous absorptive material with the vapors from a boiling mixture of an aldehyde and an aqueous hydrogen halide. 'I'his readily can be accomplished in the apparatus of the drawing.

The solid highly porous adsorptive material or solid adsorbent contact material preferably is 1n the form of porous masses providing multiplicity of passageways or a very large surface area. Although most satisfactory results are obtained employing solid highly porous adsorptive material or solid absorbent contact masses in the form of porous bodies presenting a relative large surface area of contact to the reactants in proportion to the volume, practical results can be obtained employing masses which are relatively inert as surface active material or as adsorbents.

Broadly stated, the preferred form of the continuous method for producing haloalkylated halogen substituted thiophene can be described as haloalkylating halogen substituted thiophene by co-current flowing of a stream of halogen substituted thiophene and a stream of aldehyde and liquid hydrogen halide countercurrent to a stream of vapors from a mixture of aldehyde and aqueous hydrogen halide. A simple form of the necessary equipment comprises a reboiler for aqueous aldehyde and hydrogen halide solution, a contact zone providing a tortuous path along which the liquid halogenated thiophene and liquid halide and hydrogen halide pass in countercurrent iloW to the vapors of aldehyde and hydrogen halide, means for introducing fresh aldehyde and liquid hydrogen halide, means for introducing halogenated thiophene, means for removing spent halogcn halide, means for removing reacted and unreacted halogenated thiophene, means for maintaining a predetermined temperature in the contact zone and a reilux condenser. Of course, suitable means for regis- 9 tering the temperature at 'various places in the apparatus are included.

The drawing is illustrative but not limiting, in a more or less diagrammatic manner of a unit for carrying out the continuous process of the present invention on an industrial scale.

A suitable means ofv providing a contact zone comprises a jacketed reactor i .provided with a packed section 2. The packed section 2 of the reactor is provided with packing material 3 which kmay be in the form of glass lbeads, glass helices, Raschig rings, Fiberglas bats, pellets of natural or synthetic alum-ina silica igel, silica gel, wood charcoal or activated carbon vsuch vas cocoH nut charcoal. The packing material t Vis maintained in place or `rests on a suitable shelf or base such as perforated `plate 4. Immediately beneath the reactor I is a bubble tray from which the liquid draining from the packed section 2 is removed by line 6 to heat exchanger 7 wherein it is heated in vanyv suitable mannerto a temperature at which the` hydrogen halide and. aldehyde are volatile but not more than about 250 degrees Fahrenheit. The .heated liquid is discharged from heat .exchanger 'I through `line 8 to tray il in the bottom of the reactor column. The volatile material in the heated liquid from the heat exchanger' 'l volatilizes on tray a passes up through the packed section. The nonvolatile portion of the heated liquid from heat is operated preferably 'at vreduced pressure L wherein the unreacted. halogenated thiophene is taken as an overhead and recycled through lines i5 and Iii to the top of the packed section 2 of reactor I. The crude haloalkylated halogenated thiophene is withdrawn from the recycle tower it through line Il for purification in a suitable manner.

Aqueous hydrogen halide drawn from storage not shown through line I8 and aldehyde drawn from storage through line I i! are mixed in line 2li together with recovered aldehyde-hydrogen halide discharged into line 2t from line ZI. The mixture of recovered aldehyde and hydrogen halide and fresh aldehyde and hydrogen halide in line 29- passes through line 22 to heat exchanger I2 where it absorbs heat from the acid solution from the `base of reactor I and passes through line 23 to thejtop ofpacked section 2 of reactor i. Fresh charge halogenated thiophene is drawn from storage and passed through line 2d to `line ES where mixed with recycle halogenated thiophene; the mixture -is Vpassed to the top Yof packed section 2 of reactor I.r Reactor i is provided with a reflux condenser25 into 4which the ifumes of hydrogen halidea'ndvolatile"aldeu hyde are passed through line 2S.V Coolant passes into condenser 25 through line 2l' and out through line 28. lncondensed vapors from the redux condenser 25 passed through line 2Q to the aldehyde and hydrogen halide recovery tower 3S. The aqueous liquid in the bottom. of reactor I after passing through line I I and heat exchanger IZinto line 3i is v pumped by rpump 32 through line 33 to* thetop of recovery tower 3@ vwherein it absorbs the 'vapors introduced 'into tower 3i) lil 10 through line 2S; The fortified solution is drawn from the bottom of tower 3i) through line t and mixed with fresh hydrogen halide and Yaldeh'ydc in line 29. Valve 35 provides means for discharging aqueous Vliquid from the bottom of re actor I through line S.

The preparation of halothenylhalijde in a continuous manner may be carried out with the apparatus described hereinbefore in the following-manner.: .for example, 2-chlorothiophene is drawn from storage thraugh line 24 while simultaneously aqueous hydrogen halide and Formalin solution are drawn from storage through lines I8 and I9, respectively. The aqueous mixture of hydrogen halide and formaldehyde passes through line 20 and heat exchanger l2 through line 23 to the top of packed section 2 of reactor i. A mixture of aqueous hydrogen halide and :aqueous formaldehyde is heated in heat exchanger 1in any suitable manner and discharged through line 8 to pan ii where the hydrogen halide and formaldehyde volatilize and pass lipward through packed section 2 of lrector I in countercurrent flow to the liquid aqueous hydrogen .halide and formaldehyde solution discharged from line 23v at .the top of packed section 2 of reactor I and liquid 2-chlorothiophene discharged at the top of packed section -2 of reactor i from line It. The liquid draining from packed sec tion 2 0f reactor I collects on pan 5 from which itt-.is withdrawn through 1ine 6 to heat exchanger l. The non-volatile material draining from pan 9 through pipe I0 stratires in the bottom of the reactor tower to form an aqueous layer and an oily layer. The aqueous layer is drawn ofi through line II and the oily layer is drawn off through line I3, from which it passes to recycle tower I4. In recycle tower I unreacted 2-chlorothiophene is taken as overhead through line I5 and mixed with fresh charge 2-chlorothiophene in line 25. The 5-ch1oro-2-thenylchloride formed in reactor I and removed therefrom through line I3 collects as a bottom product in recycle tower I4, from which it is withdrawn through line I1 for purification in any suitable manner, for example by fractionation. The vapors of water, hydrogen halide and aldehyde rising from packed section 2 of reactor I pass through line 26 into Vreux condenser 25 wherein the vapors are cooled by 'a Vcoolant such as water entering through line 27 and escaping through line 28. The non-condensable vapors escape from refiux condenser 25 and pass lthrough line 29 to the bottom of the aldehyde, hydrogen halide recovery tower 3B. Aqueous solution is withdrawn from the bottom of tower l Vthrough line I I, pass through heat exchange I2 into line 3i and drawn therefrom by pump 32 and passed through line 33 to the. top of tower 39. Fortied aqueous solution containing the hydrogen halide and formaldehyde escaping from the reux condenser `25 is then passed through lines 35 and 2l Vto line 2E) wherein it mixes with fresh aqueous hydrogen halide and aqueous aldeylhde.. The temperature of the reaction zone, i. e. packed section 2, .in reactor I is maintained at about 2li)` degrees Fahrenheit by the heat transmitted to the reactor by the vapors from vthe vaporizeror heatexchanger 7.

While the hydrogen halide is generally einployed 'in amounts in excess of theoretic-al proportions, the proportions :in which the halogenated Vthiophene and the aldehyde 'are reacted will be dictated ina .large measure by the economic factors cont1ol1`ing" tl1e choice. Either 'of these reactants may be used in excess of the theoretical proportion as required by the particular circumstances of a specific situation. Consequently, the molal ratio of hydrogenated thiophene to aldehyde may be varied from an excess of halogenated thiophene to an excess of aldehyde. In this relation those skilled in the art will understand that any excess of a theoretical proportion or excess is relative to the amount of each reactant as determined by the theoretical equation for the reaction which may be represented as follows:

where R is a hydrogen, an alkyl group, a benzene ring, an alkyl benzene ring or a heterocyclic ring, and X is chlorine, bromine or iodine.

I claim:

1. A method for preparing halothienyl methylhalides which comprises reacting essentially only a halothiophene having a replaceable nuclear hydrogen, formaldehydev and `aqueous hydrogen halide.

2. A method for preparing halothienyl alkylhalides which comprises reacting essentially only a halothiophene having a replaceable nuclear hydrogen, an acyclic aldehyde having 1 to 5 carbon atoms and aqueous hydrogen halide.

3. A method for preparing compounds corresponding to the formula where R is hydrogen, a mononuclear aryl group, a cycloparafn group, or an alkyl group having l to 5 carbon atoms and m is 1 to 3 and X is chlorine, bromine or iodine which comprises reacting essentially only a halothiophene having a replaceable nuclear hydrogen with an aldehyde selected from the group consisting of single ring aromatic aldehydes, formyl cycloparains and acyclic aldehydes having 1 to 5 carbon atoms and aqueous hydrogen halide.

4. A method for preparing halothienyl methylhalides which comprises reacting essentially only a halothiophene having a replaceable nuclear hydrogen with formaldehyde and aqueous hydrogen halides at temperatures above 40 degrees centigrade to the reflux temperature.

'5. A method for preparing compounds corresponding to the formula his Where R is hydrogen, a mononuclear aryl group, a cycloparamn group. or an alkyl group having 1 to 5 carbon atom-s, m is 1 to 3 and X is chlorine, bromine or iodine which comprises reacting essentially only a halothiophene having a replaceable nuclear hydrogen, an aldehyde selected from the group consisting of acyclic aldehydes having 1 to 5 carbon atoms, formyl cycloparamns and single ring aromatic aldehydes and aqueous hydrogen halide at elevated temperatures up to the reiiux temperature.

6. A method for preparing monohalothienyl methylhalides which comprises reacting monohalothophene having at least one replaceable nuclear hydrogen, formaldehyde and hydrogen halide at temperatures up to the reflux temperature.

7. A method for preparing dihalothienyl methylhalides which comprises reacting a dihalothiophene having at least one replaceable nuclear hydrogen, formaldehyde and hydrogen halide at temperatures up to reflux temperature.

8. A method for preparing trihalothienyl methylhalides which comprises reacting a trihalothiophene having a replaceable nuclear hydrogen, formaldehyde and hydrogen halide at temperatures up to reilux temperature.

9. A method for preparing compounds corresponding to the formula n HAH Where R is hydrogen, a mononuclear aryl group, or an alkyl group having 1 to 5 carbon atoms, and X is chlorine. bromine or iodine, and m is 1 which comprises reacting essentially only a monohalothiophene having at least one replaceable nuclear hydrogen with an aldehyde selected from the group consisting of acyclic aldehydes having 1 to 5 carbon atoms, formyl cycloparafns and single ring aromatic aldehydes and aqueous hydrogen halide at temperatures up to reflux temperature.

10. A method for preparing compounds corresponding to the formula where R is hydrogen, a mononuclear aryl group, or an alkyl group having 1 to 5 carbon atoms, 'm is 2 and X is chlorine, bromine or iodine which comprises reacting essentially only a dihalothiophene having at least one replaceable nuclear hydrogen, aqueous hydrogen halide and an aldehyde selected from the group consisting of acyclic aldehydes having 1 to 5 carbon atoms. formyl cycloparafns and single ring aromatic aldehydes at temperatures up to reflux temperature.

11. A method for preparing compounds corresponding to the formula Where R is hydrogen, a mononuclear aryl group, or an alkyl group having 1 to 5 carbon atoms, m is 3 and X is chlorine, bromine or iodine which comprises reacting a trihalothiophene having a replaceable nuclear hydrogen, a hydrogen halide and an aldehyde selected from the group consisting of acyclic aldehydes having 1 to 5 carbon atoms, forrnyl cycloparains and single ring aromatic aldehydes at temperatures up to reflux temperature.

12. Ay method for preparing compounds corresponding to the formula ...inria where R is hydrogen, a mononuclear aryl group, or an alkyl group having 1 to 5 carbon atoms, m is 1 to 3 and X is chlorine, bromine or iodine which gmprises intimately mixing halogenated aeaaoee thiophene having at least one replaceable nuclear hydrogen, hydrogen halide, and an aldehyde selected from the group consisting of acyclic aldehydes having 1 to 5 carbon atoms, formyl cycloparafms and single ring aromatic aldehydes at the surface of highly porous adsorptive material.

13. A method for preparing compounds correspending to the formula where R is hydrogen, a mononuclear aryl group, or an alkyl group having 1 to 5 carbon atoms, m is 1 to 3 and X is chlorine, bromine or iodine which comprises introducing liquid halogenated thophene having at least one replaceable nuclear hydrogen, hydrogen halide and an aldehyde into the upper part of a reaction Zone containing solid absorbent contact material, introducing vapors of said aldehyde and hydrogen halide into the lower part of said reaction zone, and withdrawing liquid halogenated thiophene and one of the group halothenyl halide and alpha-substituted halothenyl halide from a point in said reaction zone below the source of said aldehyde and hydrogen halide vapors.

15. 5 halothienyl 2 methylhalides having a composition corresponding to the formula 'r X -c-X where X is a halogen selected from the group consisting of chlorine, bromine and iodine.

16. 5 chloro 2 thenylchloride identied by forming with potassium ethyl xanthate a product containing 14.1 weight per cent chlorine and 38.0 weight per cent sulfur.

17 5-chloro-2-theny1 chloride.

HENRY D. NORRIS.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Name Date Blicke Aug. 19, 1947 OTHER REFERENCES Organic Reactions, vol. I, pp. 64, 65, John Wiley and Sons, 1942.

Blicke: J. Am. Chem. Soc., 64, 478 (1942).

Blicke: J. Am. Chem. Soc., 68, 1934 (1946).

Steinkopf: Die Chemie des Thiophens, p. 45, Steinkopf, Dresden, 1941.

Steinkopf: Ann. 513, 284 (1934).

Number 

17. 5-CHLORO-2-THENYL CHLORIDE. 